diff --git a/src/borg/archive.py b/src/borg/archive.py
index 68cf30bd2..ccd469e12 100644
--- a/src/borg/archive.py
+++ b/src/borg/archive.py
@@ -500,7 +500,7 @@ def __init__(
             self.tags = set()
         else:
             if name_is_id:
-                # we also go over the manifest here to avoid quick&dirty deleted archives,
+                # we also go over the manifest here to avoid soft-deleted archives,
                 # except if we explicitly request one via deleted=True.
                 info = self.manifest.archives.get_by_id(name, deleted=deleted)
             else:
diff --git a/src/borg/archiver/__init__.py b/src/borg/archiver/__init__.py
index add009bea..f8939f894 100644
--- a/src/borg/archiver/__init__.py
+++ b/src/borg/archiver/__init__.py
@@ -92,6 +92,7 @@ def get_func(args):
 from .tag_cmd import TagMixIn
 from .tar_cmds import TarMixIn
 from .transfer_cmd import TransferMixIn
+from .undelete_cmd import UnDeleteMixIn
 from .version_cmd import VersionMixIn
 
 
@@ -124,6 +125,7 @@ class Archiver(
     TagMixIn,
     TarMixIn,
     TransferMixIn,
+    UnDeleteMixIn,
     VersionMixIn,
 ):
     def __init__(self, lock_wait=None, prog=None):
@@ -364,6 +366,7 @@ def build_parser(self):
         self.build_parser_tag(subparsers, common_parser, mid_common_parser)
         self.build_parser_tar(subparsers, common_parser, mid_common_parser)
         self.build_parser_transfer(subparsers, common_parser, mid_common_parser)
+        self.build_parser_undelete(subparsers, common_parser, mid_common_parser)
         self.build_parser_version(subparsers, common_parser, mid_common_parser)
         return parser
 
diff --git a/src/borg/archiver/undelete_cmd.py b/src/borg/archiver/undelete_cmd.py
new file mode 100644
index 000000000..31e38ca51
--- /dev/null
+++ b/src/borg/archiver/undelete_cmd.py
@@ -0,0 +1,90 @@
+import argparse
+import logging
+
+from ._common import with_repository
+from ..constants import *  # NOQA
+from ..helpers import format_archive, CommandError, bin_to_hex, archivename_validator
+from ..manifest import Manifest
+
+from ..logger import create_logger
+
+logger = create_logger()
+
+
+class UnDeleteMixIn:
+    @with_repository(manifest=False)
+    def do_undelete(self, args, repository):
+        """Undelete archives"""
+        self.output_list = args.output_list
+        dry_run = args.dry_run
+        manifest = Manifest.load(repository, (Manifest.Operation.DELETE,))
+        if args.name:
+            archive_infos = [manifest.archives.get_one([args.name], deleted=True)]
+        else:
+            args.deleted = True
+            archive_infos = manifest.archives.list_considering(args)
+        count = len(archive_infos)
+        if count == 0:
+            return
+        if not args.name and not args.match_archives and args.first == 0 and args.last == 0:
+            raise CommandError("Aborting: if you really want to undelete all archives, please use -a 'sh:*'.")
+
+        undeleted = False
+        logger_list = logging.getLogger("borg.output.list")
+        for i, archive_info in enumerate(archive_infos, 1):
+            name, id, hex_id = archive_info.name, archive_info.id, bin_to_hex(archive_info.id)
+            try:
+                if not dry_run:
+                    manifest.archives.undelete_by_id(id)
+            except KeyError:
+                self.print_warning(f"Archive {name} {hex_id} not found ({i}/{count}).")
+            else:
+                undeleted = True
+                if self.output_list:
+                    msg = "Would undelete: {} ({}/{})" if dry_run else "Undeleted archive: {} ({}/{})"
+                    logger_list.info(msg.format(format_archive(archive_info), i, count))
+        if dry_run:
+            logger.info("Finished dry-run.")
+        elif undeleted:
+            manifest.write()
+            self.print_warning("Done.", wc=None)
+        else:
+            self.print_warning("Aborted.", wc=None)
+        return
+
+    def build_parser_undelete(self, subparsers, common_parser, mid_common_parser):
+        from ._common import process_epilog, define_archive_filters_group
+
+        undelete_epilog = process_epilog(
+            """
+        This command undeletes archives in the repository.
+
+        Important: Undeleting archives is only possible before compacting.
+        Once ``borg compact`` has run, all disk space occupied only by the
+        deleted archives will be freed and undelete is not possible anymore.
+
+        When in doubt, use ``--dry-run --list`` to see what would be undeleted.
+
+        You can undelete multiple archives by specifying a matching pattern,
+        using the ``--match-archives PATTERN`` option (for more info on these patterns,
+        see :ref:`borg_patterns`).
+        """
+        )
+        subparser = subparsers.add_parser(
+            "undelete",
+            parents=[common_parser],
+            add_help=False,
+            description=self.do_undelete.__doc__,
+            epilog=undelete_epilog,
+            formatter_class=argparse.RawDescriptionHelpFormatter,
+            help="undelete archive",
+        )
+        subparser.set_defaults(func=self.do_undelete)
+        subparser.add_argument("-n", "--dry-run", dest="dry_run", action="store_true", help="do not change repository")
+        subparser.add_argument(
+            "--list", dest="output_list", action="store_true", help="output verbose list of archives"
+        )
+        define_archive_filters_group(subparser)
+        subparser.add_argument(
+            "name", metavar="NAME", nargs="?", type=archivename_validator, help="specify the archive name"
+        )
diff --git a/src/borg/manifest.py b/src/borg/manifest.py
index 51785af78..7091c2907 100644
--- a/src/borg/manifest.py
+++ b/src/borg/manifest.py
@@ -336,6 +336,12 @@ def delete_by_id(self, id):
         assert not self.legacy
         self.repository.store_move(f"archives/{bin_to_hex(id)}", delete=True)  # soft-delete
 
+    def undelete_by_id(self, id):
+        # undelete an archive
+        assert isinstance(id, bytes)
+        assert not self.legacy
+        self.repository.store_move(f"archives/{bin_to_hex(id)}", undelete=True)
+
     def list(
         self,
         *,
@@ -408,10 +414,10 @@ def list_considering(self, args):
             deleted=getattr(args, "deleted", False),
         )
 
-    def get_one(self, match, *, match_end=r"\Z"):
+    def get_one(self, match, *, match_end=r"\Z", deleted=False):
         """get exactly one archive matching <match>"""
         assert match is not None
-        archive_infos = self._matching_info_tuples(match, match_end)
+        archive_infos = self._matching_info_tuples(match, match_end, deleted=deleted)
         if len(archive_infos) != 1:
             raise CommandError(f"{match} needed to match precisely one archive, but matched {len(archive_infos)}.")
         return archive_infos[0]
diff --git a/src/borg/testsuite/archiver/undelete_cmd_test.py b/src/borg/testsuite/archiver/undelete_cmd_test.py
new file mode 100644
index 000000000..8cbc18a93
--- /dev/null
+++ b/src/borg/testsuite/archiver/undelete_cmd_test.py
@@ -0,0 +1,67 @@
+from ...constants import *  # NOQA
+from . import cmd, create_regular_file, generate_archiver_tests, RK_ENCRYPTION
+
+pytest_generate_tests = lambda metafunc: generate_archiver_tests(metafunc, kinds="local,remote,binary")  # NOQA
+
+
+def test_undelete_single(archivers, request):
+    archiver = request.getfixturevalue(archivers)
+    create_regular_file(archiver.input_path, "file1", size=1024 * 80)
+    cmd(archiver, "repo-create", RK_ENCRYPTION)
+    cmd(archiver, "create", "normal", "input")
+    cmd(archiver, "create", "deleted", "input")
+    cmd(archiver, "delete", "deleted")
+    output = cmd(archiver, "repo-list")
+    assert "normal" in output
+    assert "deleted" not in output
+    cmd(archiver, "undelete", "deleted")
+    output = cmd(archiver, "repo-list")
+    assert "normal" in output
+    assert "deleted" in output  # it's back!
+    cmd(archiver, "check")
+
+
+def test_undelete_multiple_dryrun(archivers, request):
+    archiver = request.getfixturevalue(archivers)
+    create_regular_file(archiver.input_path, "file1", size=1024 * 80)
+    cmd(archiver, "repo-create", RK_ENCRYPTION)
+    cmd(archiver, "create", "normal", "input")
+    cmd(archiver, "create", "deleted1", "input")
+    cmd(archiver, "create", "deleted2", "input")
+    cmd(archiver, "delete", "deleted1")
+    cmd(archiver, "delete", "deleted2")
+    output = cmd(archiver, "repo-list")
+    assert "normal" in output
+    assert "deleted1" not in output
+    assert "deleted2" not in output
+    output = cmd(archiver, "undelete", "--dry-run", "--list", "-a", "sh:*")
+    assert "normal" not in output  # not a candidate for undeletion
+    assert "deleted1" in output  # candidate for undeletion
+    assert "deleted2" in output  # candidate for undeletion
+    output = cmd(archiver, "repo-list")  # nothing change, it was a dry-run
+    assert "normal" in output
+    assert "deleted1" not in output
+    assert "deleted2" not in output
+
+
+def test_undelete_multiple_run(archivers, request):
+    archiver = request.getfixturevalue(archivers)
+    create_regular_file(archiver.input_path, "file1", size=1024 * 80)
+    cmd(archiver, "repo-create", RK_ENCRYPTION)
+    cmd(archiver, "create", "normal", "input")
+    cmd(archiver, "create", "deleted1", "input")
+    cmd(archiver, "create", "deleted2", "input")
+    cmd(archiver, "delete", "deleted1")
+    cmd(archiver, "delete", "deleted2")
+    output = cmd(archiver, "repo-list")
+    assert "normal" in output
+    assert "deleted1" not in output
+    assert "deleted2" not in output
+    output = cmd(archiver, "undelete", "--list", "-a", "sh:*")
+    assert "normal" not in output  # not undeleted
+    assert "deleted1" in output  # undeleted
+    assert "deleted2" in output  # undeleted
+    output = cmd(archiver, "repo-list")  # nothing change, it was a dry-run
+    assert "normal" in output
+    assert "deleted1" in output
+    assert "deleted2" in output